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Biomedical subjects

M Jasiński

Publications and source records attributed to M Jasiński.

12 recordsLinked to original sources

Functional analysis of three adjacent open reading frames from the right arm of yeast chromosome XVI.

A 7.24 kb genomic DNA fragment from the yeast Saccharomyces cerevisiae chromosome XVI was isolated by complementation of a new temperature-sensitive mutation tsa1. We determined the nucleotide sequence of this fragment located on the right arm of chromosome XVI. Among the three, complete open reading frames: YPR041w, YPR042c and YPR043w contained within this fragment, the gene YPR041w was shown to complement the tsa1 mutation and to correspond to the TIF5 gene encoding an essential protein synthesis initiation translation factor. The YPR042c gene encodes a hypothetical protein of 1075 amino acids containing four putative transmembrane segments and is non-essential for growth. The gene YPR043c encoding the 10 kDa product, highly similar to the human protein L37a from the 60S ribosomal subunit, was found to be essential and a dominant lethal. We conclude that three tightly linked yeast genes are involved in the translation process.

Amino Acid Sequence

Isotype-specific regulation of MHC class II gene expression in human monocytes by exogenous and endogenous tumor necrosis factor.

The control of expression of MHC class II molecules on antigen-presenting cells is important for the induction of immunity, while aberrant expression of these molecules plays a role in the immunopathology of autoimmune diseases. This study explored the role of tumor necrosis factor alpha (TNF) in controlling the level of HLA class II mRNA in human monocytes. Exposure of monocytes to exogenous recombinant TNF (rTNF) selectively up-regulated DR alpha-mRNA but not DP or DQ alpha-mRNA. Inhibitors of TNF synthesis, pentoxifylline (PTX) and thalidomide, inhibited TNF mRNA accumulation in LPS-activated monocytes and down-regulated DR mRNA but not DP or DQ mRNA. The inhibitory effect of anti-TNF monoclonal antibody (MAb) indicated that endogenously generated TNF acted extracellularly. Anti-p75 TNF-R2 receptor and to a lesser extent anti-p55 TNF-R1 MAbs inhibited TNF-mediated up-regulation of DR mRNA and TNF mRNA. Taken together, this implies that endogenously generated TNF plays a role in controlling isotype-specific MHC class II gene expression in human monocytes/macrophages. These results may have some implications for anti-tumor response and autoimmunity.

Antibodies, Monoclonal

Modulation of monocyte antigen-presenting capacity by tumour necrosis factor-alpha (TNF): opposing effects of exogenous TNF before and after an antigen pulse and the role of TNF gene activation in monocytes.

We have previously shown that exogenous human recombinant tumour necrosis factor-alpha (rTNF), added before an antigen pulse, enhanced antigen presentation by human blood monocytes. The present study shows that, surprisingly, rTNF added after an antigen (PPD) pulse inhibited, while anti-TNF monoclonal antibody (mAb) enhanced, antigen presentation. mAbs htr-9 against p55 TNF receptor type I (TNF-RI) abrogated rTNF enhancing effect on PPD presentation and decreased presenting activity of untreated monocytes while utr-1 mAb, against p75 TNF receptor type II (TNF-RII), reversed the inhibitory effect of rTNF given after antigen pulse. PPD and rTNF when added singly induced TNF-mRNA accumulation in monocytes. Pretreatment of monocytes with rTNF followed by a PPD pulse caused an enhancement of TNF-mRNA accumulation. However, when post-treatment with rTNF was applied to PPD-pulsed monocytes, then inhibition of TNF gene expression was seen. This may point to the role of endogenously generated TNF in regulation of antigen-presenting capacity of monocytes. These studies indicate that TNF is an important regulator of monocyte antigen-presenting capacity and that the level of TNF gene activation in monocytes may be associated with their ability to present nominal antigen.

Antibodies, Monoclonal

Modulation of antigen-presenting capacity of human monocytes by HIV-1 GP120 molecule fragments.

The two fragments of HIV-1 gp120 molecule were synthesized to study their interaction with human monocytes. Previous observations indicated that recombinant gp120 fragment (aa residues 410-511) encompassing CD4 binding region (rp120cd) induced tumour necrosis factor alpha (TNF) production in monocytes, while a similar fragment (rp120) not containing the CD4 binding sequence (aa 446-511) was inactive. This paper shows that rp120cd depressed monocyte ability to present antigen (PPD) to autologous T lymphocytes while rp120 was noninhibitory. The rp120cd interacted with monocytes but not T lymphocytes. Anti-TNF receptor type A antibody (utr-1) prevented the depression of antigen presentation caused by rp120cd, which suggested a role for TNF and its receptor. The depression of antigen presentation was seen only when monocytes were treated with rp120cd before, but not after, pulse with antigen. Parallel changes were observed in PPD-induced IL-6 production. Thus, induction of TNF by gp120 may be associated with impairment of antigen-presenting capacity of monocytes seen in AIDS patients.

Antigen Presentation

Ruptured aneurysm of the sinus of Valsalva. Clinical review, treatment results.

Five patients were operated on because of ruptured aneurysm of the sinus of Valsalva. In the cases with no concomitant VSD the surgical access from the aorta was used. The aorta was opened and the Fogarty catheter was introduced to the fistula. The "wind sock" of the aneurysm was pulled back to the aorta and excised. The opening was closed with double-line pledgetted polypropylene sutures. In severe aortic incompetence mechanical prostheses were implanted. One patient had bacterial endocarditis with reopening of the fistula and aortic valve incompetence that required reoperation. All patients are in a good clinical state. We recommend the use of Dacron patches even in small aneurysms to avoid re-opening of the fistula.

Adult

Detection, by in situ hybridization using sulphonated cDNA probe, the specific mRNA for HLA-DR alpha induced in monocyte cell lines by recombinant interferon gamma.

We adopted the nonradioactive method used for blot hybridization for the detection of inducible mRNA for HLA-DR alpha by the in situ hybridization. Unstimulated and interferon gamma stimulated MonoMac6 and U937 human monocytic cell lines were used as target cells. Sulphonation of plasmid pBR322 with HLA-DR alpha cDNA insert (2 x 700 bp, in Pstl restriction site) was performed according to the manufacturer's procedure (SulfoProbe Kit, Sigma). The hybridization signals were detected with mouse monoclonal, anti-sulphonated DNA antibody, followed by immunovisualization with anti-mouse IgG-alkaline phosphatase conjugates. Unstimulated MonoMac6 and U937 cells showed few granular reaction products only in small percentage of cells (1-5%), while in IFN gamma stimulated cells the fine granular immunoenzymatic reaction was observed in the cytoplasm of majority of cells (> 80%). This method seems to be easy and rapid to perform, making it applicable for routine diagnostic purposes in tissue sections and biopsies.

Blotting, Southern

[Sexual dysfunction].

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Cultural Characteristics